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As expected, the elevation of the water in C-Pit has risen during the filling process at an accelerated rate as the water surface area has diminished. The attached graphs from the data collected by the in-situ monitors show that the C-Pit water elevation has risen from 5195 on March 16, 2007, to over 5212 by late April. The data also show that, while the potentiometric head in monitoring well CEM-001 has increased along with C-Pit water elevation, field parameter data for pH, dissolved oxygen, conductivity, and temperature have remained steady. ORP values in CEM-001 fell starting at the beginning of the data collection period on Mazch 16, and then leveled off in mid-April. The available data appears to be consistent with our present conceptual model for the site. C-Pit was cut into the Smokey Hill shale unit overlying the Ft. Hays limestone. That limestone was extracted in C-Pit, and the pit floor is at the top of the underlying Cazlile shale. C-Pit has minimal or no hydraulic outlets, and serves as a vessel that accumulates water from precipitation and upgradient sources such as canal and ditch losses. Down gradient monitoring well CEM-001 is reportedly completed in the Ft. Hayes limestone, which is approximately 15-feet thick in this area. The 40-foot well screen for CEM-001 straddles the limestone and portions of the shale units above and below this limestone. The data indicate that CEM-001 is hydraulically connected to C-Pit (as evidenced by the observed rise in head in the well), but we believe there is little flow of groundwater through the system. The data logger recorded that the water elevation in well CEM-001 took 68 hours to recover after purging it dry prior to a recent round of sampling. Even though there is a hydraulic connection between C-Pit and CEM-001, the stable field parameter data suggest attenuation of chemical constituents is taking place. Further investigation is underway to evaluate this hypothesis: CEMEX's recently submitted Technical Revision No. 8 (TR-8) outlines our proposal for additional hydrogeologic evaluation of the site, which is now in process. Piezometers and additional monitoring wells have been installed and will be instrumented and monitored to collect additional data that will be used to refine our current understanding of the system. Further sampling of water in CEM-001 will presumably confirm the attenuation of chemical constituents. CEMEX and the Division have previously discussed [he need to monitor the alluvial groundwater northeast of C-Pit and to ensure that the St. Vrain Creek alluvial system is not adversely impacted by C-Pit water. Our investigations to date have not shown any indication of connectivity to the alluvium, but we do not think it prudent to drive the fill process to the point that it excessively elevates the water in C-Pit. We therefore prefer to act conservatively, and suspend the fill operation until more conclusive data is available. Chemical data to be obtained from the alluvial well installed northeast of C-Pit as part of TR-8 (monitoring well CEM-004) should provide any observable impacts on water quality at this location. As shown by the attached water level plots from data collected by the in-situ monitors, the water elevation in C-Pit tends to drop when fill operations are paused during nights and weekend, which suggests that if [hat process is suspended, [he system will have time to equilibrate as the water mound dissipates. In addition, to address any wildlife issues related to the small remaining water surface, as soon as it was decided to suspend the fill process, bird netting sufficient to cover that surface was ordered. It is being custom sewn, and is expected on site in two weeks.